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This operator makes it possible to calculate the response of a structure subjected to a variable seismic movement in space based on a coherence function, the impedance matrix and the seismic force. These can be calculated by the software PROMISS3D. More precisely, the modal response spectral vectors (resulting from a spectral decomposition of the coherence matrix) are constructed by means of a harmonic calculation into generalized components. At the output, we obtain the spectral density (DSP) of the modal response (for a unit excitation) or the temporal acceleration response in order to derive/to establish response spectra if accelerographs are given in one or more directions.

Produces an interspectrum or tran_gene concept.